We all know how powerful scent can be — it can take us back to a place, an emotion, a different time. Certain scents can also be very helpful for relieving stress. So encouraging children to be aware of the power of their sense of smell will help them in lots of ways.
This activity is also known as "smell and tell" by Kaia Roman, who has taught mindfulness in a school setting. Give the child something fragrant to smell, whether that's a flower, a fruit, or a herb. Ask them to close their eyes while they focus on smelling the scent.
You could give them different scents and ask how each one was different, how they made them feel, and which they preferred — and why.